Cancer is the second leading cause of death in the United States, exceeded only by heart disease. It features an abnormal mass of malignant tissue resulting from excessive cell division. Cancer cells proliferate in defiance of normal restraints on cell growth, and invade and colonize territories normally reserved for other cells. Modes of cancer therapy include chemotherapy, surgery, radiation, and combinations of these treatments. Chemotherapy typically involves use of one or more compounds that inhibit cancer cell growth. While many cancer chemotherapeutic agents have been developed, there remains a need for more effective and specific therapy.